1. Field of the Invention
The invention relates to a method for controlling a graphical element on a display through manipulation of an input device, the method comprising:                measuring a plurality of components of a magnetic field related to an orientation of the input device, and        controlling the graphical element on the basis of the plurality of components.        
The invention further relates to an input device for controlling a graphical element on a display, the input device comprising:                a plurality of sensors for measuring respective components of a magnetic field related to an orientation of the input device, and        a controller for controlling the graphical element on the basis of the plurality of components.        
2. Description of the Related Art
Such a method and input device are described in U.S. Pat. No. 5,394,029. According to the known method, the orientation of an input device is determined by measuring the magnetic field at the position of the input device. This magnetic field may be the earth's geomagnetic field or a local magnetic field. The input device has three mutually orthogonal groups of Hall sensors, one for each direction of the magnetic field. The output of each of the groups is amplified and after analog-to-digital conversion, sent to a computer as three separate signals. Each of the three signals represents a respective component of the magnetic field and the signals represent, respectively, the pitch, the roll and the yaw of the input device. The known system controls computer graphics on a display in accordance with the pitch, roll and yaw signals from the input device.